Polishing pad and polishing method

ABSTRACT

A polishing pad is provided. The polishing pad, suitable for a polishing process, includes a polishing layer, an adhesive layer and at least one heat storage material. The polishing layer has a polishing surface and a back surface opposite to each other. The adhesive layer is disposed on the back surface of the polishing layer. A region where the at least one heat storage material is disposed is located above the adhesive layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of and claims the prioritybenefit of U.S. patent application Ser. No. 15/937,872, filed on Mar.28, 2018, now pending, which claims the priority benefit of Taiwanapplication serial no. 106111034, filed on Mar. 31, 2017. The entiretyof each of the above-mentioned patent applications is herebyincorporated by reference herein and made a part of this specification.

BACKGROUND 1. Field of the Invention

This invention is related to a polishing pad and a polishing method,especially related to a polishing pad that the temperature thereof maybe decreased during a polishing process and a polishing method using thesame polishing pad.

2. Description of Related Art

In the industrial component manufacturing process, a polishing processis a technique that is more commonly used today to planarize the surfaceof an object being polished. In the polishing process, a polishing fluidis provided between the surface of an object and a polishing pad. Theplanarization is performed by mechanical friction caused by the relativemotion of the object and the polishing pad with each other. Theinterface between the layers of the polishing pad is usually adhered byusing an adhesive layer. However, the temperature of the polishing padmay increase due to the friction generated during the polishing process.Therefore, the adhesive layer is prone to deterioration, deformation oradhesion decay to affect the stability of the polishing process.

Accordingly, there is a need to provide a means for decreasing thetemperature of a polishing pad during a polishing process, so that theindustry may has a choice to solve the problem above.

SUMMARY

This invention provides a polishing pad and a polishing method todecrease the temperature of a polish pad during a polishing process, soas to avoid the problem that the adhesive layer deteriorates, deforms ordecreases in adhesion due to high temperature during the polishingprocess.

In some embodiments of this invention, the polishing pad is suitable tobe used in a polishing process. The polishing pad includes a polishinglayer, an adhesive layer, and at least one heat storage material. Thepolishing layer has a polishing surface and a back surface opposite toeach other. The adhesive layer is disposed on the back surface of thepolishing layer. A region where the at least one heat storage materialis disposed is located above the adhesive layer.

In some other embodiments of this invention, the polishing pad issuitable to be used in a polishing process. The polishing pad includes apolishing layer, a base layer, a first adhesive layer, a second adhesivelayer, and at least one heat storage material. The base layer isdisposed below the polishing layer. The first adhesive layer is disposedbetween the polishing layer and the base layer. The second adhesivelayer is disposed below the base layer. A region where the at least oneheat storage material is disposed is located between the first adhesivelayer and the second adhesive layer.

In some other embodiments of this invention, the polishing method issuitable for polishing an object and includes the following steps:providing a polishing pad, wherein the polishing pad is any one of thepolishing pads described above; applying a pressure to the object topress the object on the polishing pad; and providing relative motion tothe object and the polishing pad to perform the polishing process.

Accordingly, the polishing pad of this invention may reduce the degreeof temperature increase of the polishing pad due to mechanical frictionwhen the polishing pad is used to perform a polishing process throughthe region where the at least one heat storage material is disposed islocated above on the adhesive layer or between the first adhesive layerand the second adhesive layer. Thus, the problem that the adhesive layerdeteriorates, deforms or decreases in adhesion due to high temperatureduring the polishing process is avoided.

In order to make the aforementioned and other features and advantages ofthe invention comprehensible, several exemplary embodiments accompaniedwith figures are described in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

FIG. 1 is a diagram showing a top view of a polishing pad according to afirst embodiment of the invention.

FIG. 2 is a cross-sectional diagram taking along the cross-sectionalline I-I′ of FIG. 1.

FIG. 3 is a diagram showing the relationship between time of polishingan object and polishing pad temperature of a polishing pad of theinvention and a conventional polishing pad.

FIG. 4 is a cross-sectional diagram illustrating a polishing pad along aradius direction according to a second embodiment of the invention.

FIG. 5 is a diagram showing the relationship between temperature andheat flow rate of the two heat storage materials of the invention.

FIG. 6 is a cross-sectional diagram illustrating a polishing pad along aradius direction according to a third embodiment of the invention.

FIG. 7 is a cross-sectional diagram illustrating a polishing pad along aradius direction according to a fourth embodiment of the invention.

FIG. 8 is a cross-sectional diagram illustrating a polishing pad along aradius direction according to a fifth embodiment of the invention.

FIG. 9 is a cross-sectional diagram illustrating a polishing pad along aradius direction according to a sixth embodiment of the invention.

FIG. 10 is a process flow diagram showing a polishing method accordingto an embodiment of the invention.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1 is a diagram showing a top view of a polishing pad according to afirst embodiment of the invention. FIG. 2 is a cross-sectional diagramtaking along the cross-sectional line I-I′ of FIG. 1. In detail, thecross-sectional line I-I′ is set along the radius direction. Namely,FIG. 2 is a cross-sectional diagram along the radius direction of thepolishing pad in FIG. 1.

Please refer to FIGS. 1 and 2. In this embodiment, a polishing pad 100includes a polishing track region A and a non-polishing track region B,wherein the polishing track region A is surrounded by the non-polishingtrack region B. In detail, the polishing pad 100 is suitable to be usedin a polishing process for polishing an object. When the polishing pad100 is used to polish an object, the object is placed in the polishingtrack region A. In addition, the polishing pad 100 has a rotation centerC, and the rotation center C of the polishing pad 100 is utilized as acenter for counterclockwise rotation or clockwise rotation. The rotationcenter C is the central point of the polishing pod 100, for example.

In another aspect, in this embodiment, the polishing pad 100 includes apolishing layer 110, a plurality of grooves G, an adhesive layer 120,and a heat storage material 130. In order to clearly label the polishingtrack region A and the non-polishing track region B, the grooves G areomitted in FIG. 1.

The polishing layer 110 has a polishing surface PS and a back surface BSopposite to the polishing surface PS. In this embodiment, when thepolishing pad 100 is used to polishing an object, the object contactsthe polishing surface PS of the polishing layer 110. Moreover, thepolishing pad 100 is made from a polymer, such as a polyester, apolyether, a polyurethane, a polycarbonate, a polyacrylate, apolybutadiene, or other polymer base material synthesized from suitablethermosetting resins or thermoplastic resins, for example. However, theinvention is not limited thereto.

The grooves G are disposed in the polishing surface PS of the polishinglayer 110. In this embodiment, the grooves G have a groove depth D fromthe bottom Gb thereof to the polishing surface PS. In addition, althoughthe polishing pad 100 has many grooves G along the radius direction, asshown in FIG. 2, but the invention is not limited thereto. As long asthe polish pad 100 includes at least one groove G, this is within thescope of the invention. Moreover, the distribution profile of thegrooves G may be concentric circles, eccentric circles, ellipses,polygonal rings, spiral rings, irregular rings, parallel linear shapes,radial shapes, radiation arcs, spiral shapes, dots, or XY grids, forexample.

The adhesive layer 120 is disposed on the back surface BS of thepolishing layer 110. Namely, in this embodiment, the adhesive layer 120is attached on the back surface BS of the polishing layer 110.Furthermore, the adhesive layer 120 includes, but not limited to, acarrier-free adhesive or a double-sided adhesive. The material of theadhesive layer 120 is an acrylic-based adhesive, a silicone-basedadhesive, a rubber-based adhesive, an epoxy-based adhesive, or aurethane-based adhesive, for example. However, the invention is notlimited thereto.

The heat storage material 130 is disposed in a heat storage region H. Inthis embodiment, the heat storage region H is disposed above theadhesive layer 120 and does not contact the bottom Gb of the grooves G.As described above, the grooves G have a groove depth D. The distancebetween the top edge Ht of the heat storage region H and the polishingsurface PS is larger than D. Additionally, the distance between the topedge Ht and the polishing surface PS may be optionally smaller or equalto 1.5D, so that the region where the heat storage material 130 isdisposed is larger to effectively decrease the temperature of thepolishing pad 100. From another point of view, the top edge Ht of theheat storage region H does not contact or overlap with the bottom Gb ofthe grooves G.

In this embodiment, the heat storage material 130 is dispersed in thematerial of the polishing layer 110. Namely, the heat storage material130 is distributed in a portion of the polishing layer 110. The methodof forming the polishing layer 110 includes a step of mixing the heatstorage material 130 and the material of the polishing layer 110.Specifically, the heat storage material 130 is distributed in thepolishing layer 110 below a position having a distance larger than Dfrom the polishing surface PS. A part of the polishing layer 110 thatincludes the heat storage material 130 and a part of the polishing layer110 that does not include the heat storage material 130 are combined andformed by the perfusion method, for example. In another point of view,the heat storage region H is disposed in a portion of the polishinglayer 110.

A cover layer 140 may be optionally formed to cover the heat storagematerial 130. In detail, the material of the cover layer 140 does notchemically react with the material of the polishing layer 110 or theheat storage material 130. More specifically, the material of the coverlayer 140 may be an organic material comprising a phenolic resin, aurea-formaldehyde resin, polystyrene or a polyamide, for example.However, the invention is not limiter thereto.

Additionally, the heat storage material 130 includes an inorganic heatstorage material, an organic heat storage material, or a combinationthereof. In detail, the inorganic includes, but is not limited to, ahydrate of a salt, such as CH₃COONa.3H₂O or CaCl₂.6H₂O. The organic heatstorage material includes, but is not limited to, a polyol, a fattyalcohol, a fatty acid, or an alkane. The polyol may betrimethylolpropane (C₆H₁₄O₃, TMP), for example. The fatty alcohol may betetradecanol (C₁₄H₃₀O), for example. The fatty acid may be lauric acid(CH₃(CH₂)₁₀COOH), capric acid (CH₃(CH₂)₈COOH), for example. The alkanemay be n-eicosane (C₂₀H₄₂), n-heneicosane (C₂₁H₄₄), n-docosane (C₂₂H₄₆),n-tricosane (C₂₃H₄₈), or n-tetracosane (C₂₄H₅₀).

It is worth mentioning that the heat storage material 130 undergoes anendothermic reaction at a certain temperature or in a certaintemperature range to absorb heat from surroundings, and thus the purposeof lowering the surrounding temperature is achieved. In this embodiment,the heat storage material 130 undergoes an endothermic reaction at acertain temperature within a range from the lowest temperature Tmin tothe highest temperature Tmax of the polishing pad 100 during a polishingprocess. Namely, the heat storage material 130 inevitably undergoes anendothermic reaction during the polishing process. Since the polishingpad 100 includes the heat storage material 130, the heat generated bymechanical friction may be absorbed by the heat storage material 130 toreduce the temperature increase degree of the polishing pad 100 duringthe polishing process, and thereby the purpose of effectively reducingthe temperature of the polishing pad 100 is achieved. FIG. 3 is adiagram showing the relationship between time of polishing an object andpolishing pad temperature of a polishing pad of the invention and aconventional polishing pad. From FIG. 3, it may be known that thepolishing pad of the invention has a lower temperature during the periodof the polishing process, comparing with a conventional polishing pad.

In detail, the lowest temperature Tmin may be the temperature of waterat room temperature (about 25° C.-35° C.) or the temperature of cooledwater (such as below 10° C.). This is because the minimum temperatureTmin is the surface temperature of the polishing pad 100 at the timewhen the cleaning process is performed on the polishing pad 100 in themachine idle state or the cleaning process is performed before the nextobject entering the polishing pad 100. The cleaning process mentionedabove may use water at room temperature or water after cooling. Thehighest temperature Tmax of the polishing pad varies depending on thepolishing process. For example, the highest temperature of the polishingpad is about 65° C. in an oxide polishing process; the highesttemperature of the polishing pad is about 55° C. in a copper polishingprocess; and the highest temperature of the polishing pad is about 80°C. in a tungsten polishing process. Besides, the certain temperature maybe a fixed temperature or a temperature range.

Further, the physical state or the molecular structure of the heatstorage material 130 may be changed after the endothermic reaction. Inone embodiment, the molecular arrangement of the heat storage material130 after the endothermic reaction is looser than the moleculararrangement of the heat storage material 130 before the endothermicreaction. In other words, the molecular arrangement of the heat storagematerial 130 before the endothermic reaction is closer than themolecular arrangement of the heat storage material 130 after theendothermic reaction. In an alternative embodiment, the heat storagematerial 130 undergoes a phase transition from a first solid state to asecond solid state during the endothermic reaction, and the moleculararrangements of the first solid state and the second solid state aredifferent. For example, the crystal arrangements of the first solidstate and the second solid state are different.

It is worth noting that the polishing pad 100 includes the heat storagematerial 130, as described above, so that the temperature of thepolishing pad 100 may be decreased during the period of a polishingprocess. Thereby, since the heat storage region H where the heat storagematerial 130 is disposed is above the adhesive layer 120, the adhesivelayer 120 disposed under the heat storage region H does not have theproblem of deterioration, deformation or adhesion degradation due tohigh temperature during the polishing process, so as to maintain thestability of the polishing process.

In this embodiment, the heat storage region H where the heat storagematerial 130 is disposed is not in contact with the bottom Gb of thegrooves G, so that the contact between an object and the heat storagematerial 130 may be avoided, thereby preventing scratches and negativeimpact on the polishing quality when the polishing process is performedon the object using the polishing pad 100.

In the embodiment shown in FIG. 2, although the heat storage region Hwhere the heat storage material 130 is disposed does not contact withthe bottom Gb of the grooves G, but the invention is not limitedthereto. The option of the distance between the top edge Ht of the heatstorage region H and the polishing surface PS may depend on the abrasiondegree of the polishing layer 110 when the polishing pad 100 is used. Inother embodiments, the distance from the top edge Ht of the heat storageregion H to the polishing surface PS may be D/2, 2D/3, 3D/4, 4D/5, or Dto avoid the contact between an object and the heat storage material130, thereby preventing scratches and negative impact on the polishingquality. Moreover, in some other embodiments, the object may not beeasily scratched, or the heat storage material 130 that does not easilyscratch the object is selected. Then, it may choose to distribute theheat storage material 130 over the entire polishing layer 110 of thepolishing pad 100.

Moreover, in this embodiment, the polishing pad 100 may include thecover layer 140 covering the heat storage material 130, but theinvention is not limited thereto. In some other embodiments, in the casewhere the material of the polishing layer 110 mixed with the heatstorage material 130 may seal the heat storage material 130 therein, thepolishing pad 100 may not include the cover layer 140.

In the first embodiment, the polishing pad 100 includes the heat storagematerial 130 disposed within the polishing track region A and thenon-polishing track region B, but the invention is not limited thereto.Comparing with the non-polishing track region B, the polishing trackregion A usually has a higher temperature. Therefore, the heat storagematerial 130 may be disposed within the polishing track region A only toachieve the purpose of more evenly lowering the temperature of thepolishing pad 100 during the polishing process. In other embodiments,the polishing pad may include different heat storage materialrespectively disposed within the polishing track region A and thenon-polishing track region B. The details will be described below withreference to FIG. 4.

FIG. 4 is a cross-sectional diagram illustrating a polishing pad along aradius direction according to a second embodiment of the invention.Reference may be made to FIG. 1 for a top view diagram of a polishingpad 200 of FIG. 4. The cross-sectional position of FIG. 4 may refer tothe position of the line I-I′ in FIG. 1. Please refer to FIGS. 2 and 4at the same time, the polishing pad 200 in FIG. 4 is similar to thepolishing pad 100 in FIG. 2. Therefore, the same or similar elements arerepresented by the same or similar numerals, and the relateddescriptions thereof may refer to the descriptions above and are thusomitted here. In addition, a polishing layer 210 and an adhesive layer220 are the same or similar to the corresponding ones in the firstembodiment, and the related descriptions are thus omitted here. Thedifference between the two embodiments will be described below.

Please refer to FIG. 4. In this embodiment, the polishing pad 200includes a first heat storage material 230 a and a second heat storagematerial 230 b, and both of the first heat storage material 230 a andthe second heat storage material 230 b are disposed in the heat storageregion H. From another point of view, the first heat storage material230 a is disposed within the polishing track region A, and the secondheat storage material 230 b is disposed within the non-polishing trackregion B, in this embodiment. Namely, different heat storage materialsare disposed within the different regions of the polishing pad 200 inthis embodiment.

Further, both of the first heat storage material 230 a and the secondheat storage material 230 b are dispersed in the material of thepolishing layer 210. That is, the first heat storage material 230 a andthe second heat storage material 230 b are distributed in the polishinglayer 210. The method of forming the polishing layer 210 includesrespectively forming the structural portions corresponding to thepolishing track region A and the non-polishing track region B. Themethod of forming the structural portion corresponding to the polishingtrack region A includes a step of mixing the first heat storage material230 a and the material of the polishing layer 210, for example. Themethod of forming the structural portion corresponding to thenon-polishing track region B includes a step of mixing the second heatstorage material 230 b and the material of the polishing layer 210, forexample. The first heat storage material 230 a and the second heatstorage material 230 b are distributed in the polishing layer 210 belowa position with a distance greater than D from the polishing surface PS.In an embodiment, the method of forming the polishing layer 210 mayinclude bonding to combine the two structural portions afterrespectively forming the structural portions corresponding to thepolishing track region A and the non-polishing track region B. The twostructural portions are joined by an adhesive or thermal fusion, forexample. In another embodiment, the method of forming the polishinglayer 210 includes forming the structural portion corresponding to thepolishing track region A by perfusion method and then forming thestructural portion corresponding to the polishing track region B byperfusion method. In this case, the structural portion corresponding tothe non-polishing track region B and the formed structural portioncorresponding to the polishing track region A are connected andintegrated. A part of the polishing layer 210 that includes the firstheat storage material 230 a and the second heat storage material 230 band a part of the polishing layer 210 that does not include the firstheat storage material 230 a and the second heat storage material 230 bare combined and formed by the perfusion method, for example. Fromanother point of view, the heat storage region H is disposed in aportion of the polishing layer 210.

Moreover, a cover layer 240 may be optionally formed to cover the firstheat storage material 230 a and the second heat storage material 230 b.The property and material of the cover layer 240 are the same as thoseof the cover layer 140 and thus are omitted here.

Additionally, the first heat storage material 230 a and the second heatstorage material 230 b respectively include an inorganic heat storagematerial, an organic heat storage material, or a combination thereof. Indetail, the inorganic includes, but is not limited to, a hydrate of asalt, such as CH₃COONa.3H₂O or CaCl₂.6H₂O. The organic heat storagematerial includes, but is not limited to, a polyol, a fatty alcohol, afatty acid, or an alkane. The polyol may be trimethylolpropane (TMP,C₆H₁₄O₃), for example. The fatty alcohol may be tetradecanol (C₁₄H₃₀O),for example. The fatty acid may be lauric acid (CH₃(CH₂)₁₀COOH), capricacid (CH₃(CH₂)₈COOH), for example. The alkane may be n-eicosane(C₂₀H₄₂), n-heneicosane (C₂₁H₄₄), n-docosane (C₂₂H₄₆), n-tricosane(C₂₃H₄₈), or n-tetracosane (C₂₄H₅₀).

It is worth mentioning that the first heat storage material 230 a andthe second heat storage material 230 b undergo an endothermic reactionat different certain temperatures or in different temperature ranges toabsorb heat from surroundings, and thus the purpose of lowering thesurrounding temperature is achieved. In this embodiment, the first heatstorage material 230 a and the second heat storage material 230 bundergo an endothermic reaction at different temperatures within a rangefrom the lowest temperature Tmin to the highest temperature Tmax of thepolishing pad 200 during a polishing process. Namely, both of the firstheat storage material 230 a and the second heat storage material 230 bundergo an endothermic reaction during the polishing process. As shownin FIG. 5, the first heat storage material 230 a and the second heatstorage material 230 b undergo an endothermic reaction at differenttemperatures between the lowest temperature Tmin and the highesttemperature Tmax. Since the polishing pad 200 includes the first heatstorage material 230 a and the second heat storage material 230 b, theheat generated by mechanical friction may be absorbed by the first heatstorage material 230 a and the second heat storage material 230 b toreduce the temperature increase degree of the polishing pad 200 duringthe polishing process, and thereby the purpose of effectively reducingthe temperature of the polishing pad 200 is achieved. Besides, thecertain temperature may be a fixed temperature or a temperature range.

Furthermore, the inventor found that different areas of a polishing padmay have different temperatures when the polishing pad is used toperform a polishing process on an object. That is, the polishing pad hasa temperature gradient or a non-uniform temperature profile. In view ofthis, the first heat storage material 230 a and the second heat storagematerial 230 b which undergo an endothermic reaction at differentcertain temperatures are respectively disposed within the polishingtrack region A and the non-polishing track region B of the polishing pad200, and thereby, the temperature decrease degree of the polishing pad200 in the polishing process may be more uniform. In one embodiment, thetemperature of the polishing track region A is higher than thetemperature of the non-polishing track region B when the polishing pad200 is used in a polishing process. Thereby, the temperature decreasedegree of the polishing pad 200 may be more uniform through thepolishing pad 200 including the first heat storage material 230 a andthe second heat storage material 230 b having property shown in FIG. 5,wherein a endothermic reaction temperature of the first heat storagematerial 230 a is lower than a endothermic reaction temperature of thesecond heat storage material 230 b, or a heat absorption (i.e. an areaof the endothermic peak of the first heat storage material 230 a shownin FIG. 5) of the first heat storage material 230 a is larger than aheat absorption (i.e. an area of the endothermic peak of the second heatstorage material 230 b shown in FIG. 5) of the second heat storagematerial 230 b.

Moreover, in this embodiment, the physical state or the molecularstructure of the first heat storage material 230 a may be changed andthe physical state or the molecular structure of the second heat storagematerial 230 b may be changed after the endothermic reaction. Thisproperty is the same as the property of the heat storage material 130 inthe first embodiment. Since the related description has been describedin detail in the first embodiment, and thus is omitted here.

It is worth noting that, in this embodiment, the polishing pad 200includes the first heat storage material 230 a and the second heatstorage material 230 b, so that the temperature of the polishing pad 200may be evenly decreased in the polishing process. Thereby, since theheat storage region H where the first heat storage material 230 a andthe second heat storage material 230 b are disposed is above theadhesive layer 220, the adhesive layer 220 disposed under the heatstorage region H does not have the problem of deterioration, deformationor adhesion degradation due to high temperature during the polishingprocess, so as to maintain the stability of the polishing process.

In this embodiment, the heat storage region H where the first heatstorage material 230 a and the second heat storage material 230 b aredisposed is not in contact with the bottom Gb of the grooves G, so thatthe contact between an object and the first heat storage material 230 aand the second heat storage material 230 b may be avoided, therebypreventing scratches and negative impact on the polishing quality whenthe polishing process is performed on the object using the polishing pad200.

In the embodiment shown in FIG. 4, although the heat storage region Hwhere the first heat storage material 230 a and the second heat storagematerial 230 b are disposed does not contact with the bottom Gb of thegrooves G, but the invention is not limited thereto. The option of thedistance between the top edge Ht of the heat storage region H and thepolishing surface PS may depend on the abrasion degree of the polishinglayer 210 when the polishing pad 200 is used. In other embodiments, thedistance from the top edge Ht of the heat storage region H to thepolishing surface PS may be D/2, 2D/3, 3D/4, 4D/5, or D to avoid thecontact between an object and the first heat storage material 230 a andthe second heat storage material 230 b, thereby preventing scratches andnegative impact on the polishing quality. Moreover, in some otherembodiments, the object may not be easily scratched, or the first heatstorage material 230 a and the second heat storage material 230 b thatdoes not easily scratch the object are selected. Then, it may choose todistribute the first heat storage material 230 a and the second heatstorage material 230 b over the entire polishing layer 210 of thepolishing pad 200.

Moreover, in this embodiment, the polishing pad 200 may include thecover layer 240 covering the first heat storage material 230 a and asecond heat storage material 230 b, but the invention is not limitedthereto. In some other embodiments, in the case where the material ofthe polishing layer 210 mixed with the first heat storage material 230 aand a second heat storage material 230 b may seal the first heat storagematerial 230 a and a second heat storage material 230 b therein, thepolishing pad 200 may not include the cover layer 240.

In the first embodiment, the heat storage material 130 is dispersed inthe material of the polishing layer 110 in the corresponding heatstorage region H, but the invention is not limited thereto. In otherembodiments, the heat storage material may also be in the form of aninterface layer formed in the heat storage region H in the polishingpad. The details will be described below with reference to FIG. 6.

FIG. 6 is a cross-sectional diagram along illustrating a polishing padalong a radius direction according to a third embodiment of theinvention. Reference may be made to FIG. 1 for a top view diagram of apolishing pad 300 of FIG. 6. The cross-sectional position of FIG. 6 mayrefer to the position of the line I-I′ in FIG. 1. Please refer to FIGS.2 and 6 at the same time, the polishing pad 300 in FIG. 6 is similar tothe polishing pad 100 in FIG. 2. Therefore, the same or similar elementsare represented by the same or similar numerals, and the relateddescriptions thereof may refer to the descriptions above and are thusomitted here. In addition, a polishing layer 310 and an adhesive layer320 are the same or similar to the corresponding ones in the firstembodiment, and the related descriptions are thus omitted here. Thedifference between the two embodiments will be described below.

Please refer to FIG. 6. In this embodiment, a heat storage material 330is disposed in the heat storage region H. In detail, the heat storagematerial 330 in the heat storage region H forms an interface layer 350.Namely, the heat storage region H covers the entire interface layer 350formed by the heat storage material 330. In this embodiment, theinterface layer 350 is disposed above the adhesive layer 320. In thisembodiment, the interface layer 350 is disposed between the adhesivelayer 320 and the polishing layer 310. Besides, as described above,since the heat storage region H does not contact with the bottom Gb ofthe grooves G, the interface layer 350 which is disposed in the heatstorage region H also does not contact with the bottom Gb of the groovesG.

In one embodiment, the interface layer 350 and the polishing layer 310are made by using the same mold, for example. In detail, the method offorming the interface layer 350 and the polishing layer 310 includesusing perfusion method to inject the heat storage material 330 into amold to form the interface layer 350, and then using perfusion method toinject the material of the polishing layer 310 into the mold having theformed interface layer 350 therein. However, the invention is notlimited to the above method of forming the interface layer 350 and thepolishing layer 310. The invention also may choose another method tocomplete the structure of the interface layer 350 and the polishinglayer 310.

Moreover, a cover layer 340 may be optionally formed to cover the heatstorage material 330. The property and material of the cover layer 340are the same as those of the cover layer 140 and thus are omitted here.

Additionally, the heat storage material 330 includes an inorganic heatstorage material, an organic heat storage material, or a combinationthereof. In detail, the inorganic includes, but is not limited to, ahydrate of a salt, such as CH₃COONa.3H₂O or CaCl₂.6H₂O. The organic heatstorage material includes, but is not limited to, a polyol, a fattyalcohol, a fatty acid, or an alkane. The polyol may betrimethylolpropane (TMP, C₆H₁₄O₃), for example. The fatty alcohol may betetradecanol (C₁₄H₃₀O), for example. The fatty acid may be lauric acid(CH₃(CH₂)₁₀COOH), capric acid (CH₃(CH₂)₈COOH), for example. The alkanemay be n-eicosane (C₂₀H₄₂), n-heneicosane (C₂₁H₄₄), n-docosane (C₂₂H₄₆),n-tricosane (C₂₃H₄₈), or n-tetracosane (C₂₄H₅₀).

It is worth mentioning that the heat storage material 330 undergoes anendothermic reaction at a certain temperature or in a certaintemperature range to absorb heat from surroundings, and thus the purposeof lowering the surrounding temperature is achieved. In this embodiment,the heat storage material 330 undergoes an endothermic reaction at acertain temperature within a range from the lowest temperature Tmin tothe highest temperature Tmax of the polishing pad 300 during a polishingprocess. Namely, the heat storage material 330 inevitably undergoes anendothermic reaction during the polishing process. Since the polishingpad 300 includes the heat storage material 330, the heat generated bymechanical friction may be absorbed by the heat storage material 330 toreduce the temperature increase degree of the polishing pad 300 duringthe polishing process, and thereby the purpose of effectively reducingthe temperature of the polishing pad 300 is achieved, as shown in FIG.3. Besides, the certain temperature may be a fixed temperature or atemperature range.

Further, the physical state or the molecular structure of the heatstorage material 330 may be changed after the endothermic reaction. Thisproperty is the same as the property of the heat storage material 130 inthe first embodiment. Since the related description has been describedin detail, and thus is omitted here.

It is worth noting that, as described above, in this embodiment, thepolishing pad 300 includes the heat storage material 330, so that thetemperature of the polishing pad 300 may be decreased in the polishingprocess. Thereby, since the heat storage region H where the heat storagematerial 330 is disposed is above the adhesive layer 320, the adhesivelayer 320 disposed under the heat storage region H does not have theproblem of deterioration, deformation or adhesion decay due to hightemperature during the polishing process, so as to maintain thestability of the polishing process.

Moreover, a cover layer 340 may be optionally formed to cover the heatstorage material 330, but the invention is not limited thereto. In someother embodiments, the polishing pad 300 may not include the cover layer340 that cover the heat storage material 330 in a case where the heatstorage material 330 does not flow easily to contaminate the polishinglayer 310 or the adhesive layer 320 after the endothermic reactionoccurs.

Moreover, based on the second and third embodiments, it may be knownthat the polishing pad 300 of the third embodiment may be designed byusing the same concept of the polishing pad 200 of the secondembodiment. The heat storage material 330 originally disposed in both ofthe polishing track region A and the non-polishing track region B may bereplaced by different heat storage materials respectively disposed inthe polishing track region A and the non-polishing track region B toachieve the purpose of more evenly decrease the temperature of thepolishing pad in the polishing process. Incidentally, the polishingtrack region A usually has a higher temperature than the temperature ofthe non-polishing track region B. Therefore, the heat storage material330 may dispose within the polishing track region A only to achieve thepurpose of more evenly lowering the temperature of the polishing pad 300during the polishing process.

FIG. 7 is a cross-sectional diagram illustrating a polishing pad along aradius direction according to a fourth embodiment of the invention.Reference may be made to FIG. 1 for a top view diagram of a polishingpad 400 of FIG. 7. The cross-sectional position of FIG. 7 may refer tothe position of the line I-I′ in FIG. 1. Please refer to FIGS. 2 and 7at the same time, the polishing pad 400 in FIG. 7 is similar to thepolishing pad 100 in FIG. 2, the difference between the two embodimentsis the structure of polishing pad. Therefore, the same or similarelements are represented by the same or similar numerals, and therelated descriptions thereof may refer to the descriptions above and arethus omitted here. In addition, a polishing layer 410 is the same orsimilar to the corresponding one in the first embodiment, and therelated descriptions are thus omitted here. The difference between thetwo embodiments will be described below.

Please refer to FIG. 7. The polishing pad 400 includes a base layer 460under the polishing layer 410. In detail, in this embodiment, the baselayer 460 is suitable for underlaying the polishing layer 410 in thepolishing pad 400. The material of the base layer 460 may be apolyurethane, polybutadiene, polyethylene, polypropylene, a copolymer ofpolyethylene with ethylene vinyl acetate, or a copolymer ofpolypropylene with ethylene vinyl acetate, for example, but theinvention is not limited thereto.

The polishing pad 400 includes a first adhesive layer 420 a between thepolishing layer 410 and the base layer 460. In detail, in thisembodiment, the first adhesive layer 420 a is used for adhering thepolishing layer 410 to the base layer 460. In addition, the firstadhesive layer 420 a includes, but is limited to, carrier-free adhesive,double-sided adhesive, hot-melt adhesive, or moisture-hardeningadhesive. The material of the first adhesive layer 420 a is anacrylic-based adhesive, a silicone-based adhesive, a rubber-basedadhesive, an epoxy-based adhesive or a polyurethane-based adhesive, forexample. However, the invention is not limited thereto.

The polishing pad 400 includes a second adhesive layer 420 b under thebase layer 460. In detail, in this embodiment, the second adhesive layer420 b is adhered to the back surface of the base layer 460 away from thefirst adhesive layer 420 a. That is, the base layer 460 is disposedbetween the first adhesive layer 420 a and the second adhesive layer 420b. In addition, the second adhesive layer 420 b includes, but is limitedto, a carrier-free adhesive or a double-sided adhesive. The material ofthe second adhesive layer 420 b is an acrylic-based adhesive, asilicone-based adhesive, a rubber-based adhesive, an epoxy-basedadhesive or a polyurethane-based adhesive, for example. However, theinvention is not limited thereto.

The heat storage material 430 is disposed in a heat storage region K. Inthis embodiment, the heat storage region K is disposed between the firstadhesive layer 420 a and the second adhesive layer 420 b. In detail, inthis embodiment, the heat storage region K covers the entire base layer460. That is, the base layer 460 has a thickness T, and a distancebetween the top edge Kt and the bottom edge Kb of the heat storageregion K is equal to T.

Moreover, in this embodiment, the heat storage material 430 is dispersedin the material of the base layer 460. That is, the heat storagematerial 430 is distributed in the base layer 460. The method of formingthe base layer 460 includes a step of mixing the heat storage material430 and the material of the base layer 460.

Moreover, a cover layer 440 may be optionally formed to cover the heatstorage material 430. The property and material of the cover layer 440are the same as those of the cover layer 140 and thus are omitted here.

Additionally, the heat storage material 430 includes an inorganic heatstorage material, an organic heat storage material, or a combinationthereof. In detail, the inorganic includes, but is not limited to, ahydrate of a salt, such as CH₃COONa.3H₂O or CaCl₂.6H₂O. The organic heatstorage material includes, but is not limited to, a polyol, a fattyalcohol, a fatty acid, or an alkane. The polyol may betrimethylolpropane (TMP, C₆H₁₄O₃), for example. The fatty alcohol may betetradecanol (C₁₄H₃₀O), for example. The fatty acid may be lauric acid(CH₃(CH₂)₁₀COOH), capric acid (CH₃(CH₂)₈COOH), for example. The alkanemay be n-eicosane (C₂₀H₄₂), n-heneicosane (C₂₁H₄₄), n-docosane (C₂₂H₄₆),n-tricosane (C₂₃H₄₈), or n-tetracosane (C₂₄H₅₀).

It is worth mentioning that the heat storage material 430 undergoes anendothermic reaction at a certain temperature or in a certaintemperature range to absorb heat from surroundings, and thus the purposeof lowering the surrounding temperature is achieved. In this embodiment,the heat storage material 430 undergoes an endothermic reaction at acertain temperature within a range from the lowest temperature Tmin tothe highest temperature Tmax of the polishing pad 400 during a polishingprocess. Namely, the heat storage material 430 inevitably undergoes anendothermic reaction during the polishing process. Since the polishingpad 400 includes the heat storage material 430, the heat generated bymechanical friction may be absorbed by the heat storage material 430 toreduce the temperature increase degree of the polishing pad 400 duringthe polishing process, and thereby the purpose of effectively reducingthe temperature of the polishing pad 400 is achieved, as shown in FIG.3. Besides, the certain temperature may be a fixed temperature or atemperature range.

Further, the physical state or the molecular structure of the heatstorage material 430 may be changed after the endothermic reaction. Thisproperty is the same as the property of the heat storage material 130 inthe first embodiment. Since the related description has been describedin detail, and thus is omitted here.

It is worth noting that, as described above, in this embodiment, thepolishing pad 400 includes the heat storage material 430, so that thetemperature of the polishing pad 400 may be decreased in the polishingprocess. Thereby, since the heat dispose region K where the heat storagematerial 430 is disposed is between the first adhesive layer 420 a andthe second adhesive layer 420 b, the first adhesive layer 420 a and thesecond adhesive layer 420 b disposed on two sides of the heat storageregion K do not have the problem of deterioration, deformation oradhesion decay due to high temperature during the polishing process, soas to maintain the stability of the polishing process.

Furthermore, the polishing pad 400 includes the cover layer 440 coveringthe heat storage material 430, but the invention is not limited thereto.In other embodiments, in the case where the material of the base layer460 mixed with the heat storage material 430 may seal the heat storagematerial 430 therein, the polishing pad 400 may not include the coverlayer 440.

From the first to fourth embodiments, it may be known that the polishingpad 400 of the fourth embodiment may be designed in the same concept asthe polishing pads 100˜300 of the first to third embodiments. A heatstorage region where a heat storage material is disposed is formed abovethe first adhesive layer 420 a.

From the second and fourth embodiments, it may be known that thepolishing pad 400 of the fourth embodiment may adopt the same conceptualdesign as the polishing pad 200 of the second embodiment. The heatstorage material 430 originally disposed in both of the polishing trackregion A and the non-polishing track region B may be replaced bydifferent heat storage materials respectively disposed in the polishingtrack region A and the non-polishing track region B to achieve thepurpose of more evenly decrease the temperature of the polishing pad 400in the polishing process. Incidentally, the temperature of the polishingtrack region A is usually higher than the temperature of thenon-polishing track region B. Therefore, the heat storage material 430may dispose within the polishing track region A only to achieve thepurpose of more evenly lowering the temperature of the polishing pad 400during the polishing process.

In the fourth embodiment above, the heat storage region K covers theentire base layer 460, but the invention is not limited thereto. Theinventor found that each adhesive layer has a different adhesivestrength depending on the choice of materials for each adhesive layer.The adhesive layers also have relatively different resistance to theheat generated during the polishing process. Therefore, the heat storageregion K does not necessarily need to cover the entire base layer 460.In view of this, in other embodiments, the heat storage area K may alsobe located in part of the base layer. The details will be describedbelow with reference to FIGS. 8 and 9.

FIG. 8 is a cross-sectional diagram illustrating a polishing pad along aradius direction according to a fifth embodiment of the invention.Reference may be made to FIG. 1 for a top view diagram of a polishingpad 500 of FIG. 8. The cross-sectional position of FIG. 8 may refer tothe position of the line I-I′ in FIG. 1. Please refer to FIGS. 7 and 8at the same time, the polishing pad 500 in FIG. 8 is similar to thepolishing pad 400 in FIG. 7. Therefore, the same or similar elements arerepresented by the same or similar numerals, and the relateddescriptions thereof may refer to the descriptions above and are thusomitted here. In addition, a polishing layer 510, a first adhesive layer520 a, a second adhesive layer 520 b, a heat storage material 530, and acover layer 540 are the same or similar to the corresponding ones in thefourth embodiment, and the related descriptions are thus omitted here.The difference between the two embodiments will be described below.

Please refer to FIG. 8. In this embodiment, a heat storage region Lwhere the heat storage material 530 is disposed is located between thefirst adhesive layer 520 a and the second adhesive layer 520 b. Indetail, the heat storage region L is located in a portion of the baselayer 560 adjacent to the first adhesive layer 520 a. That is, in thisembodiment, the heat storage region L is located below the firstadhesive layer 520 a. From another point of view, in this embodiment,the base layer 560 has a thickness T, and a distance between the topedge Lt and the bottom edge Lb of the heat storage area L is T/3 to lessthan T.

Additionally, in this embodiment, the method of forming the base layer560 includes a step of mixing the heat storage material 530 and thematerial of the base layer 560. A part of the base layer 560 thatincludes the heat storage material 530 and a part of the base layer 560that does not include the heat storage material 530 are combined andformed by the perfusion method, for example.

It should be noted that, in this embodiment, since the heat storagematerial 530 is bound to undergo an endothermic reaction during thepolishing process, the polishing pad 500 includes the heat storagematerial 530, such that heat generated by mechanical friction may beabsorbed by the heat storage material 530 in the polishing process.Whereby the degree of temperature increase caused by the mechanicalfriction of the polishing pad 500 is reduced to achieve the purpose ofeffectively lowering the temperature of the polishing pad 500, as shownin FIG. 3. As a result, the heat storage region L where the heat storagematerial 530 is disposed is located in a portion of the base layer 560adjacent to the first adhesive layer 520 a, so that the first adhesivelayer 520 a disposed above the heat storage area L does not have aproblem of deterioration, deformation or adhesion decay due to hightemperature during the polishing process so as to maintain the stabilityof the polishing process.

Moreover, in this embodiment, the polishing pad 500 includes the coverlayer 540 covering the heat storage material 530, but the invention isnot limited thereto. In other embodiments, in the case where thematerial of the base layer 560 mixed with the heat storage material 530may seal the heat storage material 530 therein, the polishing pad 500may not include the cover layer 540.

From the first to third, and fifth embodiments, it may be known that thepolishing pad 500 of the fifth embodiment may be designed in the sameconcept as the polishing pads 100˜300 of the first to third embodiments.A heat storage region where a heat storage material is disposed isformed above the first adhesive layer 520 a.

From the second and fifth embodiments, it may be known that thepolishing pad 500 of the fifth embodiment may also adopt the sameconceptual design as the polishing pad 200 of the second embodiment. Theheat storage material 530 originally disposed in both of the polishingtrack region A and the non-polishing track region B may be replaced bydifferent heat storage materials respectively disposed in the polishingtrack region A and the non-polishing track region B to achieve thepurpose of more evenly decrease the temperature of the polishing pad 500in the polishing process. Incidentally, the temperature of the polishingtrack region A is usually higher than the temperature of thenon-polishing track region B. Therefore, the heat storage material 530may dispose within the polishing track region A only to achieve thepurpose of more evenly lowering the temperature of the polishing pad 500during the polishing process.

From the third and fifth embodiments, it may be known that the polishingpad 500 of the fifth embodiment may also adopt the same conceptualdesign as the polishing pad 300 of the third embodiment. The heatstorage material 530 may be used to form an interface layer between thebase layer and the first adhesive layer in the heat storage area L,instead of being dispersed in the material of the base layer 560 withinthe corresponding heat storage area L in the fifth embodiment, toachieve the same invention effect. Namely, the temperature of thepolishing pad 500 may be reduced during the polishing process.

FIG. 9 is a cross-sectional diagram illustrating a polishing pad along aradius direction according to a sixth embodiment of the invention.Reference may be made to FIG. 1 for a top view diagram of a polishingpad 600 of FIG. 9. The cross-sectional position of FIG. 9 may refer tothe position of the line I-I′ in FIG. 1. Please refer to FIGS. 8 and 9at the same time, the polishing pad 600 in FIG. 9 is similar to thepolishing pad 500 in FIG. 8. Therefore, the same or similar elements arerepresented by the same or similar numerals, and the relateddescriptions thereof may refer to the descriptions above and are thusomitted here. In addition, a polishing layer 610, a first adhesive layer620 a, a second adhesive layer 620 b, a heat storage material 630, and acover layer 640 are the same or similar to the corresponding ones in thefifth embodiment, and the related descriptions are thus omitted here.The difference between the two embodiments will be described below.

Please refer to FIG. 9. In this embodiment, a heat storage region Mwhere the heat storage material 630 is disposed is located between thefirst adhesive layer 620 a and the second adhesive layer 620 b. Indetail, the heat storage region M is located in a portion of the baselayer 660 adjacent to the second adhesive layer 620 b. That is, in thisembodiment, the heat storage region M is located above the secondadhesive layer 620 b. From another point of view, in this embodiment,the base layer 660 has a thickness T, and a distance between the topedge Mt and the bottom edge Mb of the heat storage area M is T/3 to lessthan T.

Additionally, in this embodiment, the method of forming the base layer660 includes a step of mixing the heat storage material 630 and thematerial of the base layer 660. A part of the base layer 660 thatincludes the heat storage material 630 and a part of the base layer 660that does not include the heat storage material 630 are combined andformed by the perfusion method, for example.

It should be noted that, in this embodiment, since the heat storagematerial 630 is bound to undergo an endothermic reaction during thepolishing process, the polishing pad 600 includes the heat storagematerial 630, such that heat generated by mechanical friction may beabsorbed by the heat storage material 630 in the polishing process.Whereby the degree of temperature increase caused by the mechanicalfriction of the polishing pad 600 is reduced to achieve the purpose ofeffectively lowering the temperature of the polishing pad 600, as shownin FIG. 3. As a result, the heat storage region M where the heat storagematerial 630 is disposed is located in a portion of the base layer 660adjacent to the second adhesive layer 620 b, so that the second adhesivelayer 620 b disposed under the heat storage region M does not have aproblem of deterioration, deformation or adhesion decay due to hightemperature during the polishing process so as to maintain the stabilityof the polishing process.

Moreover, in this embodiment, the polishing pad 600 includes the coverlayer 640 covering the heat storage material 630, but the invention isnot limited thereto. In other embodiments, in the case where thematerial of the base layer 660 mixed with the heat storage material 630may seal the heat storage material 630 therein, the polishing pad 600may not include the cover layer 640.

From the first to third, and sixth embodiments, it may be known that thepolishing pad 600 of the sixth embodiment may be designed in the sameconcept as the polishing pads 100˜300 of the first to third embodiments.A heat storage region where a heat storage material is disposed isformed above the first adhesive layer 620 a.

From the second and sixth embodiments, it may be known that thepolishing pad 600 of the sixth embodiment may also adopt the sameconceptual design as the polishing pad 200 of the second embodiment. Theheat storage material 630 originally disposed in both of the polishingtrack region A and the non-polishing track region B may be replaced bydifferent heat storage materials respectively disposed in the polishingtrack region A and the non-polishing track region B to achieve thepurpose of more evenly decrease the temperature of the polishing pad 600in the polishing process. Incidentally, the temperature of the polishingtrack region A is usually higher than the temperature of thenon-polishing track region B. Therefore, the heat storage material 630may dispose within the polishing track region A only to achieve thepurpose of more evenly lowering the temperature of the polishing pad 600during the polishing process.

From the third and sixth embodiments, it may be known that the polishingpad 600 of the sixth embodiment may also adopt the same conceptualdesign as the polishing pad 300 of the third embodiment. The heatstorage material 630 may be used to form an interface layer between thebase layer and the second adhesive layer in the heat storage region M,instead of being dispersed in the material of the base layer 660 withinthe corresponding heat storage region M in the sixth embodiment, toachieve the same invention effect. Namely, the temperature of thepolishing pad 600 may be reduced during the polishing process.

As described above, depending on the choice of materials for eachadhesive layer, the adhesive layers may have different adhesive strengthand the adhesive layers may also have different resistance to the heatgenerated during the polishing process. In view of the above, it shouldbe understood by those of ordinary skilled in the art based on theforegoing fifth and sixth embodiments that the polishing pad of theinvention may include two heat storage regions where the heat storagematerial is disposed and respectively located in a portion of the baselayer adjacent to the first adhesive layer and a portion of the baselayer adjacent to the second adhesive layer, or include two interfacelayers respectively located between the base layer and the firstadhesive layer as well as between the base layer and the second adhesivelayer, at the same time.

FIG. 10 is a process flow diagram showing a polishing method accordingto an embodiment of the invention. This polishing method is suitablyused to polish an object. In detail, the polishing method may be appliedto a polishing process for manufacturing an industrial device, such as adevice used in the electronic industries including semiconductordevices, integrated circuits, micro-electromechanical devices, energyconversion devices, communication devices, optical devices, disks forstorage, and displays etc., and objects used for manufacturing thedevices may include semiconductor wafers, Group III-V wafers, carriersof storage devices, ceramic substrates, polymer substrates, and glasssubstrates, etc. However, the invention is not limited hereto.

Please refer to FIG. 10. First, in step S10, a polishing pad isprovided. In detail, in this embodiment, the polishing pad may be anytype of polishing pads as described in the foregoing embodiments, e.g.,polishing pad 100, 200, 300, 400, 500 or 600. Relevant descriptions ofthe polishing pads 100, 200, 300, 400, 500 and 600 have been detailedabove and thus will not be repeated here.

Next, in step S12, a pressure is applied to an object. Thereby, theobject is pressed on the polishing pad and is in contact with thepolishing pad. In detail, as previously described, the object is incontact with the polishing surface PS of the polishing layer 110, 210,310, 410, 510 or 610. In addition, the method of applying pressure tothe object is performed by using, for example, a carrier capable ofholding the object.

Thereafter, in step S14, relative motion is provided to the object andthe polishing pad, so as to perform a polishing process on the objectusing the polishing pad and achieve the purpose of planarization. Indetail, the method for providing relative motion to the object and thepolishing pad is, for example, rotating the polishing pad fixed on aplaten via rotation of the platen.

Although the invention is disclosed as the embodiments above, theembodiments are not meant to limit the invention. Any person skilled inthe art may make slight modifications and variations without departingfrom the spirit and scope of the invention. Therefore, the protectionscope of the invention shall be defined by the claims attached below.

What is claimed is:
 1. A polishing pad suitable for a polishing process, the polishing pad comprising: a polishing layer having a polishing surface and a back surface opposite to each other; an adhesive layer disposed on the back surface of the polishing layer; and at least one heat storage material, wherein a region where the at least one heat storage material is disposed is located above the adhesive layer.
 2. The polishing pad of claim 1, wherein the at least one heat storage material is dispersed in a material of the polishing layer.
 3. The polishing pad of claim 1, wherein the at least one heat storage material forms an interface layer in the region where the at least one heat storage material is disposed, and the interface layer is disposed above the adhesive layer.
 4. The polishing pad of claim 1, further comprising at least one groove disposed in the polishing surface of the polishing layer, wherein the region where the at least one heat storage material is disposed does not contact a bottom of the at least one groove.
 5. The polishing pad of claim 4, wherein the at least one groove has a groove depth D from the bottom of the at least one groove to the polishing surface, and a distance from a top edge of the region where the at least one heat storage material is disposed to the polishing surface is smaller than or equal to 1.5D and larger than D.
 6. The polishing pad of claim 1, wherein a lowest temperature of the polishing pad is Tmin and a highest temperature of the polishing pad is Tmax during the polishing process, and the at least one heat storage material undergoes an endothermic reaction at a temperature between the Tmin and the Tmax.
 7. The polishing pad of claim 6, wherein a molecular arrangement of the at least one heat storage material after the endothermic reaction is looser than a molecular arrangement of the at least one heat storage material before the endothermic reaction.
 8. The polishing pad of claim 6, wherein the at least one heat storage material undergoes a phase transition from a first solid state to a second solid state during the endothermic reaction, and molecular arrangements of the first solid state and the second solid state are different.
 9. The polishing pad of claim 1, wherein the at least one heat storage material comprises an inorganic heat storage material, an organic heat storage material, or a combination thereof.
 10. The polishing pad of claim 9, wherein the inorganic heat storage material comprises a hydrate of a salt.
 11. The polishing pad of claim 9, wherein the organic heat storage material comprises a polyol, a fatty alcohol, a fatty acid, or an alkane.
 12. The polishing pad of claim 1, further comprising a cover layer covering the at least one heat storage material.
 13. The polishing pad of claim 12, wherein a material of the cover layer does not chemically react with a material of the polishing layer or the at least one heat storage material.
 14. The polishing pad of claim 1, further comprising a polishing track region for placing a first heat storage material and a non-polishing track region for placing a second heat storage material, wherein a lowest temperature of the polishing pad is Tmin and a highest temperature of the polishing pad is Tmax during the polishing process, and the first heat storage material and second heat storage material respectively undergo endothermic reactions at different temperatures between the Tmin and the Tmax.
 15. The polishing pad of claim 14, wherein a temperature of the endothermic reaction of the first heat storage material is lower than a temperature of the endothermic reaction of the second heat storage material.
 16. The polishing pad of claim 14, wherein a heat absorption capacity of the first heat storage material is more than a heat absorption capacity of the second heat storage material.
 17. A polishing method suitable for polishing an object, the polishing method comprising: providing a polishing pad, wherein the polishing pad is the polishing pad according to claim 1; applying a pressure to the object to press the object on the polishing pad; and providing relative motion to the object and the polishing pad to perform the polishing process. 